Technical Field
The present invention relates to a device to discharge liquid and a head driving method.
Description of the Related Art
When a liquid discharging head is driven and controlled to discharge liquid, a drive waveform including multiple drive pulses is generated and output to discharge the liquid in a single drive cycle in such a manner that the liquid discharged by the multiple drive pulses is merged to form a desired droplet.
A typically known configuration includes a drive signal supplying device to supply to a piezoelectric element a drive voltage signal including a negative voltage to drive an actuator to reduce the pressure in a pressure chamber and a positive voltage to drive the actuator to increase the pressure in the pressure chamber and supplies an initial drive pulse formed of a voltage descending waveform to descend a referential voltage between a predetermined negative voltage and a predetermined positive voltage to a negative voltage, a negative voltage holding waveform to hold the negative voltage, and a voltage ascending waveform ascending the negative voltage to a positive voltage, and a single or multiple subsequent drive pulses formed of a positive voltage holding waveform to hold the positive voltage, a voltage descending waveform descending the positive voltage to a negative voltage, a negative voltage holding waveform to hold the negative voltage, and a voltage ascending waveform ascending the negative voltage to a positive voltage in a predetermined single print cycle.
In a case in which multiple drive pulses are continuously applied to a liquid discharging head to form a single droplet, it is necessary to increase the number of drive pulses or the crest value of a single drive pulse to increase the volume of the single droplet.
However, as the number of drive pulses increase, the waveform length of the drive waveform becomes longer. Similarly, as the crest value of a single drive pulse increase, the waiting time for a meniscus to be stabilized becomes longer, thereby prolonging the waveform length of the drive waveform. If the drive waveform length is prolonged, the drive frequency lowers.